Engines, including diesel engines, gasoline engines, and gaseous fuel-powered engines are used to generate a mechanical, hydraulic, or electrical power output. In order to accomplish this power generation, an engine typically combusts a fuel/air mixture. With the purpose to ensure optimum combustion of the fuel/air mixture and to protect components of the engine from damaging extremes, the temperature of the engine and air drawn into the engine for combustion must be tightly controlled. The combustion process typically generates large amounts of heat and, in order to ensure proper and efficient operation of the engine, a cooling system is required to cool fluids directed into or out of the engine, such as, for example, coolant fluid and engine oil. A typical cooling system may have one or more heat exchangers designed to cool the coolant fluid by dissipating heat from the coolant into the atmosphere, and an oil cooler designed to cool the oil by transferring heat from the oil to the coolant fluid.
To accomplish the desired operational temperature control, an internal combustion engine is generally fluidly connected to one or more different liquid-to-air and/or air-to-air heat exchangers to cool both liquids and gases circulated throughout the engine. These heat exchangers are often located close together and/or close to the engine to maximize space efficiency. An engine driven fan or pump may be disposed either in front of the engine/exchanger package to blow air across the exchangers and the engine, or between the exchangers and engine to suck air past the exchangers and blow air past the engine, the airflow removing heat from the heat exchangers and the engine. In other arrangements cooling fluids from the environment, for example water from a marine environment, can be directed through the engine/exchanger package to remove heat therefrom.
One way to ensure proper engine and engine oil temperature is to include multiple heat exchangers in the cooling system. An exemplary heat exchanger arrangement is disclosed in U.S. Pat. No. 6,418,886 to Haimerl et al. In Haimerl, a V-configured internal combustion engine includes a coolant system with multiple heat exchangers. The Haimerl cooling system includes a coolant pump with a coolant inflow line that first directs coolant through a series of heat exchangers or “cooling jackets” disposed externally and to the sides of each of the engine's cylinder banks. The coolant is then directed through the cylinder heads and then through another series of heat exchangers disposed internally, or within the “V”, and along the sides of the cylinder banks. The coolant is then guided, upon exiting the internal heat exchangers, back to the coolant pump.
As can be seen from the cooling system in Haimerl, when coolant is directed through a heat exchangers connected in series, the arrangement is not necessarily configured to provide uniform cooling among the tandemly disposed coolers. Specifically, there is at least one potential issue with series-type cooler configurations such as the one in Haimerl, in which coolant fluid (such as, for example, air) is provided at one end of the coolant flow path and passes past each heat exchanger in series as they are disposed within the coolant flow path. In such a configuration the coolant may be warmed by the first heat exchanger prior to exposure to the second heat exchanger along the coolant flow path; and, thus, the efficiency of the second heat exchanger (and any subsequent heat exchangers in the series) may be degraded due to the increased coolant temperature.